In addition to traditional arguments for expansive executive power based on the Constitution's text and history, legal scholars from John Yoo to Bruce Ackerman have based their case for broader wartime executive power on a set of fact-intensive policy arguments about the nature of the security threats today's world presents. According to this view, terrorism and associated threats in the post-Cold War world are qualitatively different from past security threats against the United States; in this changed world, a more flexible kind of executive power is required, one that requires a readjustment of the standard scheme of multi-branch deliberation. This Article contends that neither the nature of structural constitutional interpretation, nor the security policy premises on which these claims are based, support the case for the kind of expanded executive power their proponents have in mind. The Article first considers interpretive issues arising with heavy functionalist approach to the structural provisions of the Constitution. It then notes several problems with the historical argument that the post-Cold War world presents security threats categorically different from those the nation has ever before confronted. Centrally, the Article suggest that even if one agreed that the security threats facing the United States are qualitatively different from any the United States has previously faced, one would as likely be led to the opposite conclusion regarding the virtues of unfettered executive power as a functionally effective means to meet them.